Abstract Natural products remain a rich source of compounds for drug discovery. However, a significant challenge for high throughput bioassay screening against molecular targets is the isolation of bioactive compound mixture free from interfering nuisance compounds. The well-established ubiquitous nuisance compounds in plant extracts are Tannins - polyphenolic plant metabolites. Solid-phase extraction (SPE) process is now gaining recognition as a method for rapid fractionation of crude plant extracts and employed to remove nuisance compounds as well as purify and concentrate analytes before introducing them into more expensive gas- or liquid- chromatography instrumentation. Our customer discovery interviews found that the challenges with current reverse phase materials in the removal of nuisance compounds during natural product extraction include unsuitable for more than single-use, pH (degrades at basic pH) and temperature (degrades at T > 60C) restrictions, and suboptimal performance in the removal of nuisance compounds such as tannins. These technical issues affected (increased) the operational costs to manufacture the product and decreased margins. This SBIR proposal?s overall objective is to commercially develop and deploy innovative solid phase extraction cartridges that incorporate electrically-conducting all-carbon spherical microparticles (10 M diameter), synthesized using multi-walled carbon nanotubes (MWCNTs) as starting material. Under an applied voltage, this material will selectively separate tannins ? a class of nuisance compounds prevalent in plant extracts. Two specific aims will be pursued. In Aim 1, we will fabricate and characterize the solid phase extraction cartridge (months 1-2. In aim 2, we will perform proof-of-principle experiments to (a) improved retention of tannins, (b) rapid of detection trapped tannins by electrospray mass spectrometry, and (c) autoclave and reuse of the cartridge (months 3-6). Expected outcomes include 1) Identification of optimal 3D crosslinked MWCNT powder solid (porosity, coating thickness, and applied electrical voltage) phase extraction cartridge. 2) Significantly better removal of tannin nuisance compounds compared commercially available silica C18 and graphitic hypercarb material. 3) Use of the cartridge for rapid, sensitive detection of tannins by electrospray mass spectrometry. 4) Reuse of the cartridge for multiple cycles without compromising performance. The scientific insights from the phase 1 activities will lay the foundation for the scale-up of our product as well as apply it for the removal of other nuisance compounds. Upon complete development, NanoPak-C will attract customers seeking next-generation performance capabilities fall outside the capabilities of current reverse phase materials for the removal of nuisance compounds during natural product extraction and further separation of active drug candidates from the purified extracts of natural products.